Hydeqgen sulphide in the separa



Sept. 25 1923. v1,468,988

C. BERTHELOT PROCESS 4FOR UHLIZING GASES communie HYDROGEN suLPHlDE 1N THE SEPARATION OF' METALS Filed July 14 1920 Charlar .Bert at.

.dliorn gy.

Patented Sept. 2,5, 1923.

PATENT OFFICE.

: BEBTHELOT, F PARIS, FRANCE.

PnocEss Fon U'rrLz'nm GASES cou'rnmuo Hrnnoonu sULrmDE IN THE surm- 'rIoN or METALS.

Appliaen illed July 14, 1920. Serial No. 398,295.

T o all whom t may concern;

Be it known that CHARLES BERTHELOT, a citizen of the Republic of France, and a resident of Paris, SeinefFrance, has invented certain `new and useful Improvements in Process for Utilizing Gases Containing H drogen Sul hide in the Separation of etais (for w ich I have tiled an application in France November 21, 1918), lo of which the following is a full, clear, and

exact description, such' as will enable others skilled in the art to which it appertains to curry out the Same.

The invention has for its object a process l5 for utilizing the hydrogen sulphide produced by the carbonization of combustibles, or any gas consisting wholly of or only in part hydrogen sulphide, for the chemical separation of'copper, zinc and other metals. n The method of chemical separation of copper and of zinc by means of hydrogen sulphide is not unknown, but up to the present it has never been thought to utilize for this purpose the sulphureted-hydrogen contained in the gas produced by the carbonization of orgame-Ieslles, which by carbonisation-give oit hydrogen sulphide. Coal gas specially contains from 5 to 10 grams of hydrogen sulphide er cubic metre. It is 10 well known .that t e sul hur compounds contained in the gas used goth for lighting purposes and motive power constitute pre]- udiciel impurities which necessitate costly installations to eliminate: whereas, on the "15 zontrary, by the process, which is the object of the present invention, the sulphur is made to\ become a very valuable byproduct, inly needing for its oxidization the oxygen contained in the air although other oxidizing 1U agents could be made use of.

By illustrating for an example the sepa lation ot' copper and zinc, the process `.vill readily be understood, reference being made to the annexed diagram:

The solution of sulphate of copper and of sulphate of zinc. which results either from the eating away of brass by the action @fsulpliuric arid, or by the solution in sul- Plrldriiacid of residues of brass mixed with "it meri Substances. or by an)v other way in which the sulphurii- :wid works: upon thc bqss, i5 put in direct comm-t ith the produced b the carbonization of combustibles (gas :or lighting purposes, gas from coke retorts, etc).

The copper sulphite formed is collected separately, dryed and oxidized either by a dry or wet process to transform it into sulphate of copper, when its c stallization is e'eeted in the manner alreiidY known.

As to the solution of the su hate of zinc and the sulphuric acid, it is age plete precipitation of the co per, partially removed from the circuit, wlien it is Sulliciently rich in sulphate of zinc. This salt is for the moet part separated by crystallization whilst the mother waters are again made use of for the dissolving of other quantities of brass residues.

The accom anyin diagram gives 'an example of a sc eme or such an installation:

1 represents the satnrating tank which may be of any design, provided the sulphate of copper and splphate'o'f zinc in solution is put in contact with the In the form of saturating tankshown 1n the drawing, the gas enters the inlet pipe 2, and is forced through the solution; and after contact with the solution leaves the tank `by the outlet 3. The copper sulphide .is extracted from the tank in which 1t is precipitated .by means of a steam or compressed air ejector 4',`which drives it into a drainin this separation can be e ectedby means of decantation or iiltration. The sulphate of zinc-sulphuric acid solution returns to the saturating tank by way of the receptacle 6 through the connecting tubes, whilst the coppersulphirle is separated from its mother liquor and dried in the centrifugal dryer 7, the mother waters running into the receptacle 6 and thence to the saturating tank 1. The copper sulphide is then oxidized in the oven 8, from which it emerges in the form of copper sulphate. This passes into the dissolving tank 9, and then the solution is lcft to repose for crystallization inthe receptacle 10.

The sulphate of copper crystals are dried in the centrifugal dryer 11. The mother waters accruing. as also those issuing from tanks` l0 are collected in the receptacle 12, ,thence they are forced by any means into ille dissolving tank 9.

r the comreceptacle 5, but

When the solution is sufficiently rich in sulphate of zinc, there is removed (after the complete precipitation of the copper) a certain portion, which is replaced by an equal quantity of sulphuric acid and zinc sulphate solution coming from the tank 15. and which is left to repose in the receptaclcs 13. The sulphate of zinc crystals so separated are dried in the centrifugal dryer 14. The mother waters issuing from 13 and 14 are caught in the reservoir 15, where they have added to them the fresh acid necessary to compensate for the inevitable but small losses in sulphuric acid.

The sulphuic acid and zinc sulphate solution are finally forced into the receptacle 16, where it attacks the residues of the brass introduced, for example, into the hopper 17. The copper sulphate, zinc sulphate and snlphuric acid are collected in storage reservoirs and then forced into the satnrating tank.

If the brass be mixed with inert substances, these substances, after the complete solution of the brass, are Idried in 19 in order to recover the adherent sulphnric acid, which passes into the receptacle 15.

It may be pointed out that thismethod allows of the complete recovery of the sulphur from the gas treated, as well as the perfect separation ofthe copper and zinc sul hates.

'Pixis method is moreover applicable in a general way for the treatment of solutions 'here other metals are mixed with the copper and the zinc, and to those where` the copper and the zinc is present in the state of salts other than sulphate.` It can `for instance, be applied to the treatment of solutions resulting from the action of any acids on brass, bronze, alloys or more ory less compo'nnd ores.

The same rocess may also be applied for separating t e copper from 4the nickel in solutions of alloys of the said metals, notably nickeled plates, or where the said met. als are mixed whatever the acid used for these solutions.

Again, this process can be ap lied for the separation or copper and auminium in the solutions result-ing from the treatment with acidy of bronze, of aluminium or of every 'other mixture of copper and o al uminium.

, Moreover, the same process can be made use of for the separation of tin from other metals. This method allows an economic saving of the tin in the residue of tinned sheet iron.

The process of this invention can also be applied for the production of sulphates without the expenditure of sulphuric acid. Taking for example the production of sulphate of copper, u solution oi' sulphate is treated by the gas of carbonization containing sulphureted hydrogen. the sulphide oflcopper is precipitated and the sulphuric acld is reconstituted The sulphuric acid separated from the sulphide of copper is made use of to dissolve a new quantity of copper residues for example; as to the sulphide of copper, it is oxidized either by a wet or dry means to be transformed by the process already known into sulphate.

In the process described above it is said that the said process is only utilizing the ,hydrogen sulphide contained in the gas when this acid is in free state. That supposes consequently the recovery, that is to say the elimination, of the ali. .ionia Still it couldbe found useful in certain cases to use the hydrogen sulphide when same is combined with the ammonia of the gas.

This new ap lication of a known principle can be emp oyed for example to the sep- 1aration of copper from tin.

Thus having described the nature of the invention, and explained the process in practice, I herewith declare that what I claim is:

1. The process of separating copper from zinc consisting in treating a solution containing these metals with hydrogen sulphide, separating the precipitated copper sulphide and then dissolving further quantities of the metals with the remaining solution.

2. The process of separating copper from zinc consisting in treating a so ution contain- .ing these metals with hydrogen sulphide,

separating the precipitated copper sulphide dissolving further quantities of the metals with the remaining solution and repeating the separation and dissolving of the metals until the remaining solution is sniliciently enriched in a compoundof zinc that separation by crystallization may be accomplished.

3. The process of separating copper from zinc consisting in treating a solution containing these metals with hydrogen sulphide,

separating the precipitated copper sulphide dissolving further quantities of the metals" with a part of the remaining solution and replacing the said withdrawn part by a solution of the metals formed from preceding withdrawn parts.

4. The process ci separatinpr copper fom zinc consisting ir treating a solution containing these metals with hydrogen sulphide, separating the precipitated copper sulphide, dissolving further quantities of the metals with a part of the remaining.r solution. replacing the said withdrawn part by a solution ot' the metals formed from preceding withdrawn parts and repeating the sepa ration and dissolving of thc metals until the part of the solution withdrawn after separation is sufficiently' enriched in a compound of zinc not separated from the solution that separation by crystallization may be aceomplished.

5. The process of separating copper from zinc consisting in treating;r an aciditied solution containingr these metals with l1 drogen sulphide, separating the precipitate copper sulphide. dissolving further quantities of the metals with the remaining: solution and repeatinglr the separation aud dissolving of the metals until the remaining solution is suilieiently enriched in a compound of zinc that seiaration hy crystallization may be accomplished, separating by crystallization the constituents enrichin" the solution and dissolving further quantities of the metals with the mother liquor resulting from the crystallization.

'6. The process of separating cop Jer from zine consisting in treating,r an aeidilied solution containing.r these metals with h drogen sulphide, separating.r the precipitate copper sulphide dissolving further Quantities 0f the metals with a part ofthe remaining solution and replacing;f the said withdrawn part yby a solution ot' the metals formed by preceding withdrawn parts.

The prot-ess of separatinglr copper from zimcousistin; in treating an aeidified ,solution containing these metals with hydrogen lsulphide` separating the precipitated copper sulphide` dissolving: further quantities ot' the metals with a part of the remaile iup solution and replacing;r the said withA drawn part hy a solution of the metals l'orrued hy precedingr withdrawn parts and repeatin.;r the separation and dissolving;l of the metals.

H. 'lhe process of Separating copper from zine consisting in treating,r an acidified solution containing these metals with hydrogen sulphide, separating the precipitated copper sulphide. dissolving further quantities of` the metals with a part of the remaininpr solution, replacin the said withdrawn part hy a solution of t e metals formed from preceding withdrawn parts and repeating the separation and dissolvinf of the metals until the part of the solution withdrawn after separation is suflieiently 'enriched in a compound of Zine not separated from the solution that separation by crystallization may he accomplished.

9. The process of separating copper from zinc consisting,y in treating an aciditied solution containing these metals with hydrogen sulphide, separating the precipitated copper sulphide. dissolving further quantities o the metals with a part of the remaining solution` replacingl the said withdrawn part by a solution of the metals formed from preredingr withdrawn parts and repeating the separation and dissolving` of. the metals until the part of the solution withdrawn after separation is sufficiently enriched in a compound ot' zine not separated from the solution that separation by crystallization may he accomplished. separating hy cristallization the zinc compound enriching` the said part and dissolving further quantities ot' the metals with the mother liquor result-V ing from the cr \'stallization.

ln witness whereof. l have hereunto signed my name this 12th day of June. 1920. in the present-c of two subscribing witnesses.

CHARLES BERTHICLU'I.

W itnesses:

ANDR BRUNET, CLEMENT S. Eowanns. 

